REMOTE PREPARATION OF AN ARBITRARY TWO-PARTICLE PURE STATE VIA NONMAXIMALLY ENTANGLED STATES AND POSITIVE OPERATOR-VALUED MEASUREMENT

2010 ◽  
Vol 08 (08) ◽  
pp. 1265-1275 ◽  
Author(s):  
DONG WANG

A scheme for remotely preparing an arbitrary two-particle pure state is proposed by employing bipartite nonmaximally entangled states as quantum channels. During the preparation, two auxiliary particles and an optimal positive operator-valued measurement are introduced. The preparation of two-particle pure states can be remotely realized with certain success probability (SP). And the SP of our scheme is exactly worked out. It turns out that the SP depends inherently on the quantum channels employed beforehand. Furthermore, we find that, as far as two special ensembles of two-particle states are concerned, i.e. real and equatorial-like, the SP can be enhanced to quadruple.

2013 ◽  
Vol 27 (28) ◽  
pp. 1350155 ◽  
Author(s):  
N. METWALLY

The dynamics of a general two qubit system in a noninetrial frame is investigated analytically, where it is assumed that both of its subsystems are differently accelerated. Two classes of initial traveling states are considered: self-transposed and generic pure states. The entanglement contained in all possible generated entangled states between the qubits and their anti-qubits is quantified. The usefulness of the traveling states as quantum channels to perform quantum teleportation is investigated. For the self-transposed classes, it is shown that the generalized Werner state is the most robust class and starting from a class of pure state, one can generate entangled states more robust than self-transposed classes.


2012 ◽  
Vol 10 (05) ◽  
pp. 1250062 ◽  
Author(s):  
ZHAO LI ◽  
PING ZHOU

We present a scheme for multiparty-controlled remote preparation of an arbitrary m-qudit (d-dimensional quantum system) state via positive operator-valued measurement (POVM) by using nonmaximally entangled states as the quantum channel, not resorting to auxiliary qubits. The sender performs an optimal POVM measurement on her m particles with measurement operators that depend on the original state, the controllers perform generalized X-basis measurement X d and the receiver can prepare the original state if he cooperates with all the controllers and the sender. The scheme has the advantage of having high success probability for remote preparing an arbitrary m-qudit state and more convenient than others in a practical application. Moreover, it discusses the relationship between the probability that the receiver obtains the originally state and the coefficients of the entangled states.


2014 ◽  
Vol 12 (03) ◽  
pp. 1450011 ◽  
Author(s):  
Pengfei Xing ◽  
Yimin Liu ◽  
Chuanmei Xie ◽  
Xiansong Liu ◽  
Zhanjun Zhang

Two three-party schemes are put forward for sharing quantum operations on a remote qutrit with local operation and classical communication as well as shared entanglements. The first scheme uses a two-qutrit and three-qutrit non-maximally entangled states as quantum channels, while the second replaces the three-qutrit non-maximally entangled state with a two-qutrit. Both schemes are treated and compared from the four aspects of quantum and classical resource consumption, necessary-operation complexity, success probability and efficiency. It is found that the latter is overall more optimal than the former as far as a restricted set of operations is concerned. In addition, comparisons of both schemes with other four relevant ones are also made to show their two features, including degree generalization and channel-state generalization. Furthermore, some concrete discussions on both schemes are made to expose their important features of security, symmetry and experimental feasibility. Particularly, it is revealed that the success probabilities and intrinsic efficiencies in both schemes are completely determined by the shared entanglement.


2022 ◽  
Author(s):  
Zhan-Yun Wang ◽  
Feng-Lin Wu ◽  
Zhen-Yu Peng ◽  
Si-Yuan Liu

Abstract We investigate how the correlated actions of quantum channels affect the robustness of entangled states. We consider the Bell-like state and random two-qubit pure states in the correlated depolarizing, bit flip, bit-phase flip, and phase flip channels. It is found that the robustness of two-qubit pure states can be noticeably enhanced due to the correlations between consecutive actions of these noisy channels, and the Bell-like state is always the most robust state. We also consider the robustness of three-qubit pure states in correlated noisy channels. For the correlated bit flip and phase flip channels, the result shows that although the most robust and most fragile states are locally unitary equivalent, they exhibit different robustness in different correlated channels, and the effect of channel correlations on them is also significantly different. However, for the correlated depolarizing and bit-phase flip channels, the robustness of two special three-qubit pure states is exactly the same. Moreover, compared with the random three-qubit pure states, they are neither the most robust states nor the most fragile states.


2011 ◽  
Vol 09 (01) ◽  
pp. 539-546 ◽  
Author(s):  
LIAN-FANG HAN ◽  
HAO YUAN

We propose two protocols for remotely preparing a two-qubit entangled state, where the quantum channels take the form of one-dimensional four-qubit cluster and cluster-class states, respectively. The total success probability and classical communication cost are also calculated.


2001 ◽  
Vol 1 (3) ◽  
pp. 52-61
Author(s):  
P Aravind

Positive operator valued measures (POVMs) are presented that allow an unknown pure state of a spin-1 particle to be determined with optimal fidelity when 2 to 5 copies of that state are available. Optimal POVMs are also presented for a spin-3/2 particle when 2 or 3 copies of the unknown state are available. Although these POVMs are optimal they are not always minimal, indicating that there is room for improvement.


2017 ◽  
Vol 16 (10) ◽  
Author(s):  
Jiahua Wei ◽  
Lei Shi ◽  
Lihua Ma ◽  
Yang Xue ◽  
Xuchun Zhuang ◽  
...  

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 352 ◽  
Author(s):  
Zhan-Yun Wang ◽  
Yi-Tao Gou ◽  
Jin-Xing Hou ◽  
Li-Ke Cao ◽  
Xiao-Hui Wang

We explicitly present a generalized quantum teleportation of a two-qubit entangled state protocol, which uses two pairs of partially entangled particles as quantum channel. We verify that the optimal probability of successful teleportation is determined by the smallest superposition coefficient of these partially entangled particles. However, the two-qubit entangled state to be teleported will be destroyed if teleportation fails. To solve this problem, we show a more sophisticated probabilistic resumable quantum teleportation scheme of a two-qubit entangled state, where the state to be teleported can be recovered by the sender when teleportation fails. Thus the information of the unknown state is retained during the process. Accordingly, we can repeat the teleportion process as many times as one has available quantum channels. Therefore, the quantum channels with weak entanglement can also be used to teleport unknown two-qubit entangled states successfully with a high number of repetitions, and for channels with strong entanglement only a small number of repetitions are required to guarantee successful teleportation.


2011 ◽  
Vol 09 (06) ◽  
pp. 1437-1448
Author(s):  
YI-BAO LI ◽  
KUI HOU ◽  
SHOU-HUA SHI

We propose two kinds of schemes for multiparty remote state preparation (MRSP) of the multiparticle d-dimensional equatorial quantum states by using partial entangled state as the quantum channel. Unlike more remote state preparation scheme which only one sender knows the original state to be remotely prepared, the quantum state is shared by two-party or multiparty in this scheme. We show that if and only if all the senders agree to collaborate with each other, the receiver can recover the original state with certain probability. It is found that the total success probability of MRSP is only by means of the smaller coefficients of the quantum channel and the dimension d.


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